Rear lower control arm upgrades - good or bad idea?

[kcjaz]

I asked this question in a thread I started about rear lower control arm (RLCA) frame mount skids and wasn't getting as much input as I was hoping for so I am making this its own thread.

My question is this: Is upgrading the RLCAs worth it or even a good idea? You can spend a lot of money on stronger arms like the Icons ($750) but I wonder how much better they can really be in terms of not getting bent if you land one on a rock. For $350, I could just carry two spare OEM arms. I rather just replace a damaged $150 arm then bend an Icon and have to replace it.

Some have pointed out, including @afgman786 in my other thread, that if the upgraded arms are stronger, the next thing to think about is what is the next component that would break? i.e. maybe the control arm survives but the mounting point breaks. I understand that in general and it may apply here too but I really wonder if any of the commercially available upgraded RLCA's will really not bend if they land hard on a rock and end up supporting the truck rather than a wheel or frame rail.

The next thing I wonder, is how often do people really destroy their RLCAs? I know this happens but how much of a problem is it? I'm my mind, even if an arm gets bent on the trail, it isn't likely a catastrophic event requiring a recovery or field repair to get off the trail. Yes your rear axle alignment will be affected but the truck will still drive. Maybe not the 600 highway miles home but at least off the trail. Does worrying about it too much even make sense?

 

[Markuson]

I’ e gone through three RLCAs. Two bent on the trail...one of the replacements bent by a careless shop that misaligned the shop lift and bent one. So OEMs both bent on trail & replaced with SPC. Shop bent the SPC, so I replaced it and have a spare SPC now.

None of my bends were catastrophic and had no dramatic impact on driving.

I’ve seen several Icons break ends badly on the forum, and one in person.

The forward pivot/mount on the 200 is a weak point tho IMO, and definitely susceptible to damage...so I would protect that regardless.

To answer your question about whether it’s worth simply upgrading...no...IMO it’s not worth upgrading perfectly good OEMs until you bend or damaged them.

 

[Hants]

I have upgraded the rear arms on my 80... bent an OEM one in Moab, after many years of wheeling hard.

The forward mount was fairly eroded from rock rash, but still functional/strong.

When I bent it, driving wasn’t very much impaired (still drove straight on the freeway). At that time, upgraded to Slee and never looked back.

I’d say, upgrade them when/if you bend them. May want to put armor on the mounts before, if your usage is banging them up.

 

[afgman786]

As above stated, I wouldn't drop the coin on the upgraded ones if the ones you have are fine. You'd really need to damage them badly to not be able to get off the trail and get home. I know when I damage mine, I plan on replacing with factory since there is that big price difference and it's not like the factory trail arms are tooth picks.

 

[kcjaz]

As above stated, I wouldn't drop the coin on the upgraded ones if the ones you have are fine. You'd really need to damage them badly to not be able to get off the trail and get home. I know when I damage mine, I plan on replacing with factory since there is that big price difference and it's not like the factory trail arms are tooth picks.

I agree. I think the factory ones are pretty robust. From a few google searches looks like $250 gets a pair of SPC "upgraded" arms compared to $300 for a pair of OEM arms. Maybe there is a better price out there for OEM. I'm going to put this way down on the list. At most, I may buy a pair to have in my spare parts inventory (someday when I actually have a spare parts inventory....). For now, I'll just focus on trying to keep my tires on top of the tall rocks and my RLCAs off them.

 

[BlackMammoth]

I have Icon billet UCAs but I am not comfortable have a billet aluminum beam for a lower control arm.

Icon does make a steel version but not sure there is any magic to it over the competing brands.

 

[kcjaz]

So I bent my OEM RLCA and am now thinking about upgrades again. I bought an OEM one as a spare and will just put it on for now.

Upgrade options appear to be:

Metal Tech
SPC
Superior Engineering
Total Chaos? There is reference to this in another thread but I don't see RLCAs for 200's on their website
ICON -Billet and tubular
Sleeve or truss OEM RLCAs locally
Anything else??

Some of these are adjustable but I saw in another thread @Taco2Cruiser warn that the jam nut can require trimming of the of the frame mount. Sure enough, the install instructions for the ICON billet arms show this a "may be required on some models". For $800 I would have higher expectations than having to weaken the frame attachment to add stronger arms.

I've also seen posts recommending the OEM bushings over poly I believe because of squeaks.

I like the concept of the rectangular cross section of the ICON billets over a hollow tube just from a theoretical strength perspective but ICON makes these out of aluminum. I'm sure they are stronger that OEM but maybe not Metal Tech's.

Superior Engineering look good but their web site has no detailed spec data to know what they really are. I like that they are not adjustable with no jam nut to cause interference requiring trimming of the frame mount. Anyone running these?

I am really temped to just sleeve and/or truss my OEM arms. I'm sure I would end up with something better than the ICON billet and not spend as much. I'd probably end up spending more than just buying Metal Tech's or Superior Engineering but they may be stronger.

I

 

[Tex68w]

Sleeve and truss the stockers gets my vote.

 

[CharlieS]

Trail Tailor also offers a lower arm, but they currently show out of stock for the 200 on the web site.

I bent one of mine, and noticed it during an underbody inspection. Not surprising how the get tweaked with how exposed they are.

I'm pretty new to technical trails, and I try hard to pick good lines, but I'm not always successful. No matter how great a line you pick, occasionally you just have to send it to get over an obstacle and it seems like these are the most exposed and low hanging bits other than the shock mounts and diff.

I'm trying to figure out my next move, but I'll probably just replace my bent one with a stock arm. I may weld some steel angle to them, but probably not.

 

[afgman786]

Down side would be you could be moving the weak point to the frame mount if your new arms are stronger than that.

 

[kcjaz]

Down side would be you could be moving the weak point to the frame mount if your new arms are stronger than that.

Yes, there is always the next weakest link when you start down the path of making components stronger. So it’s something to look at for sure. My gut tells me that the frame and axle mounts are strong enough to take take any loads caused by hitting the RLCA or even bouncing it on rock.

I’m searching for “how to sleeve” a RLCA on the net right now and not finding much. I’m just curious on how it is usually done. Seems like you would have to cut one end off and reweld it. That would seem to potentially create some other issues and fab quality would be important.

May post on the 80 forum as I think those guys do this. Anyone know how this is typically done? Any YouTube links?

 

[CharlieS]

It might have been back in my 80 series days, but I seem to recall people welding steel angle to the underside to strengthen and make something like a skid surface.

 

[CharlieS]

Post about sleeving: Rear Lower Control Arms Mod - 80 series - https://forum.ih8mud.com/threads/rear-lower-control-arms-mod-80-series.451110/

Angle: Rear Control Arm Mod - https://forum.ih8mud.com/threads/rear-control-arm-mod.270027/post-4205138

And the more I read on mud, all generations of modern Lc with this suspension setup have the same issue with the rlca and rlca mounts, so those smarty-pants comments about picking a better line deserve an old fashioned 'mud salute.

 

[kcjaz]

thanks @CharlieS. The sleeving thread is great. I don’t like the “cut OEM arm in half” part. I get that you have to cut it but doing so means you no longer get any strength from the OEM tube. Cutting near on end would be better.

I wonder if the OEM bushings are replaceable. If they are then the modifications possible are greater. Searching…

 

[turbo8]

thanks @CharlieS. The sleeving thread is great. I don’t like the “cut OEM arm in half” part. I get that you have to cut it but doing so means you no longer get any strength from the OEM tube. Cutting near on end would be better.

I wonder if the OEM bushings are replaceable. If they are then the modifications possible are greater. Searching…

Even though I have TC rear links, I'm going to go back to stock. The TC links are really noisy and let more vibrations into the chassis. I didn't gain anything from them other than they are are stronger. Since the stock LCA are a little weak I came up with a bolt on gusset\slider. I will be test fitting these around xmas and had a few extra made.

Machined parts are 6061 aluminum and the slider is 304 stainless.

 

[kcjaz]

Even though I have TC rear links, I'm going to go back to stock. The TC links are really noisy and let more vibrations into the chassis. I didn't gain anything from them other than they are are stronger. Since the stock LCA are a little weak I came up with a bolt on gusset\slider. I will be test fitting these around xmas and had a few extra made.

Machined parts are 6061 aluminum and the slider is 304 stainless.

View attachment 2848902

View attachment 2848903

Looks pretty cool! I was thinking about cutting a sleeve tube along its axis making two clam shells and then seam welding it around the OEM RLCA. I like the bolt on idea.

 

[kcjaz]

Found a good video of a guy replacing the RLCA bushings on a Forerunner. The OEM bushings can be pressed out. The guy replaces the OEM with aftermarket poly bushings and talks about how lube is important to minimize the squeaking. I don't have any personal experience with poly bushings in an application like this but anything that needs lube to not squeak and isn't sealed needs to be greasable (IMO). Having to drop the RLCAs out and pop out the bushings just to re-grease would be a pain.



With the OEM bushings removed, welding on the OEM arms can be done without fear of trashing the bushings.

I can't find the OEM bushing part number and am not certain you can buy them separately though that would seem dumb. This diagram shows it but no number.

 

[audyssey]

These are the only pics I have of my upgrade. Buddy owns a body shop so he has all the tools/welding skills. Modified the RLCAs one weekend, then painted over the week, then installed the following weekend.

I bent my passenger side RLCA:

Measured the OD of the RCLAs:

Ordered new OEM RCLAs and purchased dom carbon steel tube: 1.75" od x .188" wall x 24"
1.75" - (2x .188") = 1.374" (~34.9mm)

Cut the new RCLAs in half then sleeved them inside the DOM:

Cut the DOM to the correct length then used in a drill press to drill 6 (12 holes) rotated 90° for the middle ones) on each tube.
Inserted the split DOM in the tubes and then welded the RCLAs at the drilled holes and completely around the ends.

 

[kcjaz]

These are the only pics I have of my upgrade. Buddy owns a body shop so he has all the tools/welding skills. Modified the RLCAs one weekend, then painted over the week, then installed the following weekend.

I bent my passenger side RLCA:
View attachment 2849307

Measured the OD of the RCLAs:
View attachment 2849308

Ordered new OEM RCLAs and purchased dom carbon steel tube: 1.75" od x .188" wall x 24"
1.75" - (2x .188") = 1.374" (~34.9mm)

Cut the new RCLAs in half then sleeved them inside the DOM:
View attachment 2849309

Cut the DOM to the correct length then used in a drill press to drill 6 (12 holes) rotated 90° for the middle ones) on each tube.
Inserted the split DOM in the tubes and then welded the RCLAs at the drilled holes and completely around the ends.

View attachment 2849312

Nice. Is that some heat damage on the bushings near the welds? I am concerned about welding near the ends with the bushings installed.

 

[audyssey]

Yes, there was a little bit of heat damage. Should have slowed down and let them cool, but we were being impatient. We'll see how long those bushings hold up.